The present McClain effect invention pertains to projectiles having improved in-flight performance. More particularly, the invention concerns projectiles with surface and subsurface aerodynamical characteristics which induce self-stabilizing spinning action and reduce drag effects, with attendant improvements in kinetic energies, range, accuracy and flight stability. Projectiles benefiting from the invention include ballistic missiles, small arms projectiles and explosive shells, artillery shells, shot pellets, and the like. The invention has application to projectiles fired into all forms of fluid, propelled in any manner and at all velocities.
Stone projectiles were first fired via catapults, which advanced after the Chinese invention of gun powder to stone spheres propelled by primitive explosive gases in smooth bore launch tubes. Later additions to projectiles were brass, iron and bronze spheres. The advent of the United States Civil War brought into being the rifled bore launch tube, and the rifling generated spin which materially improved range and quite possibly the kinetic impact energy of projectiles. Most modern day projectiles of streamline shape are launched via rifled bores, propelled by nitrocellulose gases at about 2700.degree. C. and 14,000 times expansion into gases by volume of the nitrocellulose.
Projectiles fired from launch tubes having rifled bore generally have greater accuracy and range over similar projectiles fired from smooth bore launch tubes. The rifling in the bore imposes a spin on projectiles traveling through the launch tube. As a spinning projectile (i.e., rotating about its longitudinal axis) travels through the air, the spinning action tends to reduce the effects of drag and compression waves to slow the forward velocity and the rotation of the projectile. The present invention with its surface aerodynamical design characteristics acts to extend these advantages to projectiles fired from smooth bore launch tubes. It is to be noted, however, that the invention also has application to projectiles fired from rifled bores. In general, the projectiles of the invention have increased velocity, accuracy, and longer ranges, while retaining kinetic energies, over similar projectiles which do not incorporate the invention.
Projectiles which are spin stabilized achieve a high rate of rotation as the projectiles travel over their trajectories. Such rotation may range between about 300 and about 2,000 radians per second. These high rotation speeds for known smooth-surface projectiles generally are imparted by conventional projectile driving bands which extend around the exterior circumference of such projectiles. The bands engage rifling in launch tubes as the projectiles are fired through the tubes.
As noted above, projectiles fired from smooth launch tubes generally lack the velocity, kinetic energies, range and accuracy of smooth projectiles fred from rifled barrels. In the past a number of efforts have been made to modify the projectiles fired from smooth launch tubes; however, these modifications have failed to bring about the desired amounts of improvement. The modifications have included the installation of such features as fins and dimples on the exterior surface. While some improvements have been realized by such features, much more improvement remains to be obtained.